1. Field of the Invention
The invention relates generally to a roof for a refrigerator or freezer building and in particular to a roofing system that prevents thermal conduction into the building and allows venting of the roof.
2. Prior Art
FIG. 1 is a cross sectional view of a conventional roof for a refrigerator or freezer building. A deck 3 is attached to purlins 2 through mechanical fasteners 4. An insulation board 8 is placed on top of the deck 3 and attached to the deck 3 by mechanical fasteners 10. A vapor barrier 7 is placed over the insulation board 8. This roof construction has several disadvantages. Because the fasteners 10 extend from the warm side of the roof to the cool side of the roof, thermal conductivity occurs through fasteners 10 thus reducing the cooling efficiency of the refrigerator or freezer building. The vapor barrier 7 must be placed on the warm side of the roof. In a refrigerator/freezer building, this is outside of the building. Because the vapor barrier 7 is formed on the top of the roof, there is no way to vent the roof.